Packaging apparatus and method of packaging



w. c TAYLOR 3,370,394 7 PACKAGING APPARATUS AND METHOD OF PACKAGING Feb. 27, 1968 15 Sheets-Sheet 1 Filed Jan. 7, 1966 INVENTOR.

WESLEY C. TAYLOR BY MAHONEY, MILLER & RAMBO ATTORNEYS Feb. 27', 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING I Filed Jan. 7, 1966 15 Sheets-Sheet 2 WESLEY C. TAYLOR BY MAHONEY. MILLER & RAMBO WW KM ATTORNEYS Feb. 27, 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING Filed Jan. 7, 1966 15 Sheets-Sheet I3 I INVENTOR.

WESLEY c. TAYLOR BY MAHONEY, MILLER & RAMBO ATTORNEYS Feb. 27, 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING l5 Sheets-Sheet 4 Filed Jan. 7, 1966 INVENTOR.

WESLEY C. TAYLOR MAHONEY,MI LLER & RAM 0 ATTOR N E YS Feb. 27, 1968 w. CJTAYLOR 3,370,394

7 PACKAGING APPARATUS AND METHOD OF PACKAGING l5 Sheets-Sheet 5 Filed Jan. 7, 1966 INVENTOR.

WESLEY C. TAYLOR BY MAHONEY, MILLER & RAMBO ATTORNEYS Feb. 27, 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING Filed Jan. 7, 1966 15 Sheets-Sheet 6 INVENTOR.

WESLEY c. TAYLOR BY [I] MAHONEYJWLLER & RAMBO BY 4a.-

ATTORNEYS m mx Q Q w. c. TAYLOR 3,

PACKAGING APPARATUS AND METHOD OF PACKAGING Feb. 27, 1968 15 Sheets-Sheet '7 Filed Jan. 7, 1966 Feb. 27, 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING Filed Jan. 7, 1966 15 Sheets-Sheet 8 7 Q l 9 I JC I Q m Q N & II Q N m Q Q Q f l 4 Hum I I m I I \I I N l 1 1 l I I I N N J N QB j Q 1 J I L II 'I I u m Q Q Q u m N Q K? LI l Q91 0 l INVENTOR.

E47, '5 f WESLEY c. TAYLOR BY MAHONEY,MILLER & RAM 0 ATTORNEYS Feb. 27, 1968 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING W. C. TAYLOR l5 Sheets-Sheet 9 Filed Jan. 7, 1966 INVENTOR.

WESLEY C. TAYLOR UH rm W A m R E a m fl m M A M Y MW y HE A v M Feb. 27, 1968 v w. c. TAYLOR 7 PACKAGING APPARATUS AND METHOD OF PACKAGING Filed Jan. 7, 1966 15 Sheets-Sheet 1O INVENTOR.

WESLEY C. TAYLOR BY MAHONEY. MILLER & RAMBO ATTORNEYS Feb. 27, 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING Filed Jan. 7, 1966 15 Sheets-Sheet 11 INVENTOR.

WESLEY C. TAYLOR BY MAHONEY. MILLER & RAM 0 ATTORNEYS w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING Feb. 27, 1968 15 Sheets-Sheet 12 Filed Jan. 7, 1966 INVENTOR.

WESLEY C. TAYLOR BY MAHONEY, MILLER & RAMBO ATTORNEYS Feb. 27, 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING l5 Sheets-Sheet 15 Filed Jan. 7, 1966 INVENTOR. WESLEY c. TAYLOR MAHONEY MILLER & RAMBO va KM ATTORNEYS Feb. 27, 1968 w. c. TAYLOR v r 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING 15 Sheets-Sheet 14 Filed Jan. 7, 1966 INVENTOR. WESLEY C. TAYLOR BY MAHONEY, MILLER & RAMBO ATTORNEYS Feb. 27, 1968 w. c. TAYLOR 3,370,394

PACKAGING APPARATUS AND METHOD OF PACKAGING Filed Jan. 7, 1966 4 l5 sheets-sheet ls R A w 3 v/ /v/ m g I L L Q INVENTOR. WESLEY c. TAYLOR L 6 MAHONEY. MILLER a. RAMBO BY 8 8 ATTORNEYS United States Patent 3,370,394 PACKAGING APPARATUS AND METHOD OF PACKAGING Wesley C. Taylor, Columbus, Ohio, assiguor of one-half to The Cottiugham Paper Co., Columbus, Ohio, a corporatiou of Ohio Filed Jan. 7, 1966, Ser. No. 519,217 11 Claims. or. 53-33 This relates, in general, to method and packaging apparatus for mechanically wrapping articles in a pliable material supplied in a continuous, elongated web. It relates, more specifically, to method and packaging apparatus which is capable of utilizing a pliable wrapping ma terial of the type characterized as a resilient, heat-scalable, soft-film and performs the wrapping operation with concurrent, longitudinal and transverse stretching of the film.

Mechanical packaging apparatus of the known prior art has been designed only for utilizing wrapping material having a degree of stiffness of at least a predetermined minimum value. Such prior art apparatus as is known is usually of the type which engages the leading edge of the web of wrapping material and is adapted to draw the material through the wrapping machine in engagement with the article to be wrapped with additional components or elements sequentially actuated to engage the film at desired points and complete selected portions of the Wrapping operation. In order to accomplish their objective, the prior art machines are limited to utilization of a wrap ping material having a predetermined stillness to provide limited self-support during portions of the wrapping operation. This is necessary as these machines do not continuously engage and support the material during all stages of a wrapping operation and the several elements selectively engage the film at predetermined times for performance of their respective operations. Since the film will be unsupported at times, it must have adequate stiffness to maintain a desired position where the elements may readily engage and grasp the material at the appropriate point in the wrapping operation.

It is often desired to obtain an article wrap in which the material is tightly drawn about the article to further exclude air thereby enhancing the article preservation capabilities of the package. As one expedient, the packaging machines of the prior art have been adapted to utilize a material which is characterized as a heat-shrinkable material and, subsequent to the wrapping operation, the wrapped article is subjected to a heating operation which will shrink the material and thereby obtain the desired result of tightly drawing the film about the article. Although this technique is capable of providing a tightly wrapped article as desired, there is a limitation in that some articles may not be subjected to a heating operation.

Consequently, materials (such as the heat-shrinkable, polyvinyl chloride films) have been developed which may be preliminarily stretched and, when Wrapped about an article and released, will contract and thereby draw tightlv about the article. These materials, while having the desired resi ient characteristics, are referred to as softfilms in that the stiffness characteristic is well below the predetermined minimum value which is required for utilization with the prior art machines. Such soft-film materials are incapable of providing the necessary self-support and must be continuously supported or restrictively engaged during the wrapping operation. Release of such a soft-film material during a wrapping operation, after it has been removed from a customary supply roll, will result in the film folding about itself into an unusable mass. The several elements of the wrapping machines for performing the folding operation will, therefore, be unable to grasp the material and perform the desired function.

ice

It is, therefore,.the objective of this invention to provide a method and packaging apparatus which is capable of utilizing a soft-film wrapping material and perform a wrapping operation in which such a resilient, pliable, softfilm material is first stretched and then permitted to contract and draw tightly about the article to exclude air from the article. The packaging apparatus of this invention is capable of performing the desired operation as it incorporates elements and components which continuously engage and support the film during the wrapping operation. The elements engage the material at the beginning of the wrapping cycle and only release their respective portions of the film at times during the Wrapping cycle when their respective operations are completed and continued support or restrictive engagement is unnecessary. Concurrently with the continuous engagement and support of the film during the wrapping operation, the several elements of the packaging apparatus are selectively operable to effect both longitudinal and transverse stretching of the film whereupon, subsequent to release, the material will contract to form a tightly wrapped package.

It is a further object of this invention to provide a method and packaging apparatus for utilizing a soft-film, heat-scalable material and capable of performing a completely automatic wrappin operation which concludes with heat-sealing operations for bonding overlapped portions of the material together.

It is also an object of this invention to provide a method and packaging apparatus capable of utilizing a soft-film, resiliently pliable wrapping material supplied in a continuous web form and which is operable to mechanically complete an article wrapping operation in an automatically controlled sequence.

These and other objects and advantages of this invention will be readily apparent from the following detailed description of an embodiment of the packaging apparatus of this invention and the accompanying drawings.

In. the drawings:

FIGURE 1 is a top plan view of a packaging apparatus embodying this invention.

FIGURE 2 is a front end elevational view taken along lines 22 of FIGURE 1.

FIGURE 3 is a left side elevational view as seen in FIGURE 1 with a portion of the supporting structure broken away.

FIGURE 4 is a fragmentary vertical sectional view on an enlarged scale taken along line 44 of FIGURE 1.

FIGURE 5 is a vertical sectional view similar to FIG- URE 4 but showing the several elements as displaced during a wrapping operation.

FIGURE 6 is a fragmentary top plan view of that portion of the apparatus shown in FIGURE 4.

FIGURE 7 is a vertical elevational view taken along line 77 of FIGURE 6.

FIGURE 8 is a vertical sectional view taken along lines 8-3 of FIGURE 6.

FIGURE 9 is a fragmentary sectional view of the clamping mechanism and associated support and actuating mechanism taken along line 9-9 of FIGURE 1.

FIGURE 10 is a transverse sectional view taken along lines 10-1ll of FIGURE 9.

FIGURE 11 is a top plan view of the clamp as seen in FIGURE 9 with a portion of one jaw broken away showing the center member.

FIGURE 12 is an enlarged fragmentary top plan view taken along lines 12-12 of FIGURE 5 showing structure details of the spreader finger mechanism at the right side of the apparatus.

FIGURE 13 is a transverse sectional view taken along lines 1313 of FIGURE 12.

FIGURES 14 through 23, inclusive, are diagrammatic,

vertical sectional views similar to FIGURE 4 sequentially illustrating a wrapping operation.

FIGURE 24 is a diagrammatic illustration of a wrapped article showing the fold and seal lines.

FIGURE 25 is a diagrammatic vertical sectional view taken along lines 25-25 of FIGURE 18 showing the transverse stretching of the film and operation of the spreader fingers.

FIGURE 26 is a vertical sectional view taken along line 2626 of FIGURE 22 showing the operation of the A supply conveyor 32 is also preferably provided for' utilization with the apparatus to facilitate automatic operation of the apparatus. This supply conveyor comprises an endless belt 33 which extends between the side walls 31 and is trained about a supporting end roller structure 34 at a receiving station relative to the several elements of the packaging-apparatus. The opposite end of the supply conveyor 32 is positioned adjacent a loading station which may be the discharge station of a machine (not shown) which provides the articles that are to be wrapped by the packaging apparatus. Details of construction of the end roller structure 34 are not shown in the several figures as their specific construction is well known and does not form a part of this invention. A discharge conveyor 35 for the packaging apparatus may also be provided, as shown in FIGURES 1, 2 and 3, to receive the wrapped articles and convey them from the packaging apparatus at the conclusion of the wrapping operation. The discharge conveyor 35 is of the endless belt type having one end thereof forming a receiving station and trained about a supporting roller structure 36 generally located beneath the severalelements of the packaging mechanism. This supporting roller structure 36 for the discharge conveyor includes a pair of upstanding brackets 37 which are secured to the base plate 30. Both the supply conveyor 32 and the discharge conveyor 35 are driven and controlled by means external to the packaging apparatus and are not shown with the supply conveyor being driven in timed relationship to the operation of the packaging apparatus to deliver an article to the apparatus at a predetermined time.

The soft-film wrapping material utilized by the packaging apparatus of this invention is supplied in an elongated web form with'the web being wound on a suitable reel structure 38. This reel structure includes a central, cylindrical mandrel M on which the film F is wound. Supporting the reel R of soft-film wrapping material in operative relationship to the several elements of the packaging apparatus is a reel-supporting structure carried by the side walls 31in upwardly spaced relationship to the base plate 30. This reel supporting structure comprises a pair of shaft. elements 39 which are rigidly bolted to the side walls 31 in relatively fixed relationship and which project laterally therefrom and toward each other in axially aligned relationship. Secured to the inwardly'projecting free end of one shaft 39in fixed relationship is avreelengaging disc 40 of circular shape. This disc 49 is formed with an annular rim which interfits with a circular ferrule 41 fixedly mounted in the open end of the mandrel M on which the soft-film F is wound. The ferrule 41 and the disc 40 are preferably formed from a suitable metal, such as steel, and form a bearing structure with the ferrule adapted to revolve about the annular rim of the disc. The opposite Shaft 39 is also provided with a similar reelgated bar 46 which carries a centrally positioned roller 4 engaging disc 42; however, this disc is mounted on a central hub 43 which is axially movable on the shaft 39 but not rotatable. Movement of the disc 42 axially toward the respective supporting side wall 31 will disengagethe disc from the circular ferrule 41 of the reel mandrel M and permit removal or replacement of a reel. Installation of a reel structure 38 for use with the packaging apparatus is accomplished by a reverse of this operation. The circular reel-engaging disc 42 and associated hub 43 are first displaced axially to enlarge theaxial spacing and then returned to a supporting position in relation to the mandrel M of the reel. A biasing force to. insure maintenance of the disc 42 in engagement with the reel mandrel is provided by a compression spring 44 of the helically Wound, coil type which is mounted on the shaft 39. This spring-bears against the hub 43 and a stop on the shaft 39. By appropriately selecting the compression spring 44, a predetermined frictional force will be produced between the discs 40 and 42 and the respective ferrules 41 of the mandrel M to restrict or otherwise retard the rotation or revolution of the reel R and prevent inadvertent unreeling of the fihn F.

Positioned between the reel structure 38 and the operative elements of the packaging mechanism is a guide bar 45 comprising an elongated, cylindrical bar extending between and rigidly secured to the side walls 31. The guide bar 45 is provided with a relatively rotatable sleeve 45a and is positioned a predetermined distance from the reel R of film F and forms a fixed. point from which the film may be drawn into or towards the elements of the packaging apparatus.

A slack take-up mechanism is also provided in association with the reel structure 33 to assist in maintaining the proper tension on the film F as it is drawn from the reel R. The slack take-up mechanism includes an elon- 47. The bar 46 and roller 47 extend transversely to the longitudinal dimension web of film F and parallel to the guide bar 45 and reel R. Each end of the bar 46 is formed with a laterally projecting bracket 48 having a bearing structure 49 secured to the end thereof and adapted to be journaled on a respective one of the shafts 39 to permit vertical swinging movement of the bar 46 and roller 47 which forms an eccentricallymounted' weight. At the initiation of an unreeling operation, the inertia and frictional forces of the reel structure 38 and reel supporting structure tend to resist unreeling and the slack portion of the film is taken up resulting in an upward swinging movement of the roller 47 to provide a relatively constant tension although the rate of movement of the film P will be at a constant velocity. At the conclusion of an un-' reeling operation, the film F would tend to continue to un -eel as the rotational friction of the reel structure 38 and reel supporting structure would not be'capable of immediately stopping its rotation and thereby increase the slack portion of the film. The roller 47 may then swing downwardly to accommodate the greater length of film which has been unreeled thereby maintaining the film under a substantially constant tension;

The packaging apparatus, as best seen in FIGURES l, 2 and 3, comprises clamping means 50 adapted to en gage and support longitudinal, marginal edge portions of the film F, and article-supporting table 51 to assist in sup porting the article during the wrapping operation, folding and sealing mechanisms 52 and 53 adapted to successively operate on respective portions of the film to complete the wrapping operation, and driving means 54 for the preceding elements which includes a cam-type timing and actuation mechanism. Incorporatedv with .the driving means 54 is an electrical circuit havingsuitable control and sensing devices such as are necessary to provide an automatic operational cycle for a wrapping. operation. This electrical circuit is shown inFIGURE 27 with the several conductor-s being omitted from the other figures to enhance the clarity of illustration of the mechanical structure. The addition or incorporation of the electrical conductors and their connections will be understood and readily accomplished by those skilled in the art.

Primary requirements of the packaging apparatus in accomplishing the previously stated objectives are the capability of releasably engaging and supporting the film during the wrapping operation and to stretch the film in both longitudinal and transverse directions. These objectives are accomplished'by the clamping means 50 comprising a pair of identical clamping mechanisms which are supported by the side walls 31 in diametrically opposed relationship for cooperatively engaging and gripping opposed, longitudinal marginal edge portions of the film. Both clamping mechanisms are driven in synchronism through a suitable mechanical connection to the driving means 54. Through cooperative rotational and relative axial movement, the clamping mechanisms envelop the article within the film F and concurrently stretch the film in longitudinal and transverse directions.

One clamping mechanism is shown in detail in FIG- URES 9, l0 and 11 and is the clamping mechanism appearing at the left side of FIGURES l and 2. Each clamping mechanism comprises a clamping jaw assembly 60, and clamp-supporting shaft 61 on which the jaw assembly is carried for rotational and axial movement, and a cam mechanism 62 for actuating the elements of the clamping mechanism. Mounted in an aperture 63 formed in a respective side wall 31 is a bearing housing 64 in which the clamp-supporting shaft 61 is rotatably supported. The bearing housing 64 is of elongated, cylindrical form having one end thereof projecting through the aperture 63. The elongated bearing housing 64 is desired to provide adequate support for the shaft 61 in order that bending forces resulting from the cantilevered support of the shaft 61 and jaw assembly 60 may be more adequately resisted. Formed about the exterior of the bearing housing 64 is an annular bolt flange 64a to facilitate fastening of the bearing housing to the vertical side wall 31 by suitable capscrews 65. A driving connection to the clamp-supporting shaft 61 is provided by a sprocket gear 66 having an elongated, tubular hub 67. The elongated hub 67 projects axially through the bearing housing 64 and is journaled in a pair of bearing assemblies 68 disposed at opposite ends of the housing. These bearing assemblies 63 may be of the well known ball bearing type to resist radial and thrust forces. Formed at one end of the clampsupporting shaft 61 is an externally-splined extension 69. The shaft extension 69 is inserted in the cooperatively splined, axial bore 70 of the hub 67. This splined connection permits relative axial sliding movement of the shaft 61 relative to the side wall .31 while transmitting rotational movement to the shaft by means of the sprocket gear 66. A thrust plate 71 may be threaded .onto the inboard end of the sprocket gear hub 67 to provide increased resistance to axial movement of the hub and sprocket gear.

The clamping jaw assembly 66, which is carried at the unsupported end of the shaft 61, forms a double clamp structure with each section adapted to independently engage and support respective longitudinally spaced marginal edge portions of the film F. Each clamping section of the jaw assembly 60 includes a common, central anvil member 72 which is rigidly secured or attached to the shaft 61 in fixed relationship and is rectangularly shaped having an elongated marginal edge portion disposed transversely to the shaft axis. Also carried by the shaft 61 are a pair of independently operable clamping plates 73 and 74 which cooperate with the central anvil member 72 and are designated herein as the bottom and top clamping plates. Each clamping plate 73 and 74 is rectangularly shaped having an elongated marginal edge portion adapted to overlie an opposed marginal edge portion of the member 72 and is pivotally connected to the shaft 61 for swinging movement in a plane normal to the center member 72. The hinge structure for pivotally connecting each clamping plate, 73 or 74, to the shaft 61 can be best seen in FIGURE 11. With reference to this figure, each plate 73 or 74 is seen to be formed with a recess 75 extending along a marginal edge portion which is adapted to receive a hinge block 76 secured to the end of the shaft 61. Extending longitudinally of the respective plates 73 or 74 and journaled in the hinge block 76 is a pivot pin 77.

Secured to a face of each of the movable clamping plates 73 and 74 along a longitudinal marginal edge portion is an elongated strip of frictional material 78 which cooperates with the center member 72 to enhance the clamping and gripping effectiveness of the jaw assemblies. Normally biasing each of the clamping plates 73 and 74 into clamping relationship with the center member 72 is a biasing spring 79. The biasing spring 79, which may be of the helical coil type, is mounted on the hinge pin 77 which is exposed in the recess 75 of the respective clamping plate and cooperatively engages the shaft 61 and respective plate to provide the biasing force.

The length of the respective plates 73, 74 and center member 72 is determined by the average length of the article on which the packaging machine is designed to perform a wrapping operation. Thus, the size of the package which may be wrapped may be slightly greater or less than the length of the longitudinal edge portion covered by the frictional material 7 8.

Actuation of the clamping jaw assembly 68 as to its clamping operation and as to its axial movement relative to the side walls 31 is effected by the cam mechanism 62. This cam mechanism 62 comprises a cylindrical hub having a central axial bore 81 adapted to receive an end of the supporting shaft 61. Formed on the exterior of the cam mechanism 62 is an annular bolt flange 31 to facilitate attachment of the cam mechanism to the side walls 31 by means of suitable fastening devices, such as the cap screws 82. Formed on the interior of the hub and extending circumferentially around the bore 86 are three independent, relatively axially spaced cam races or tracks 83, 84 and 85. Each of the cam tracks is adapted to be cooperatively engaged by a respective cam follower S6, 87

and S8 for operation of the shaft 61 and the top and 'bottom clamping pates 73 and 74. The cam follower 86 comprises a radially extending lug formed on the exterior of the supporting shaft 61. Each of the cam followers 87 and 88 is formed with a respective actuating link 89 and 99 which is connected with a respective top or bottom clamping plate, 74 or 73. Longitudinally extending guide slots 91 and 92 are formed in the supporting shaft 61 for receiving the respective connecting links 89 and 99 and to permit relative sliding axial movement. Each of the cam races 83, 84 and extends circumferentialiy around the interior of the bore 80 forming a predetermined path which will result in actuation of the shaft 61 or the clamping plates 73 and 74 in a desired timed relationship to the rotational movement of the shaft. Thus, as the shaft 61 is rotated by means of the sprocket gear 66 through a mechanical connection to the driving means, the cam follower 86 of the shaft will engage the cam track 83 and result extension or retraction of the shaft and clamping jaw assembly 66' relative to the siie wall 31. Similarly, the connecting links 89 and 90 will be axially displaced relative to the shaft 61 through cooperative reaction of their respective cam followers $6 and 87 wi'h the respective cam races 84 and 85. Assuring retention of the links 89 and 90 in their respective slots 91 and 92 are a pair of U-shaped guide brackets 103 which are rigidly fastened to the shaft 61 adajcent the jaw assembly 60. Each link 89 and 99 is free to slide in its respective slot axially of the shaft 61 but will be prevented from being displaced radially as a consequence of the operation of the jaw assembly. This axial movement of the connecting links 89 and 90 is transmitted as rotational swinging movement to respective clamping plates 74 and 73 through a hinge connection. This hinge connection for each clamp- 4 ing plate 74 and '73 includes a short lever arm 93 projecting laterally from the surface of the respective clamping plate. Formed in each of the lever arms 93 is an elongated slot 94 which receives a pivot pin 95 carried by the respective link 89 or 90. The elongated slot 94 is necessary to accommodate the arcuate movement of the lever mechanical interconnection with the driving means 54.. l

The driving means 54, as diagrammatically illustrated in FIGURE 27, includes an electric motor 96 having an output shaft 97. Connected to the output shaft 97 is an electromagnetic clutch assembly 98 which is operable to permit intermittent operation of the packaging apparatus although the motor 9-6 is continously operated. Driven by the clutch assembly 98 is a drive shaft 99 which extends transversely of the side walls 31 of the packaging machine structure and is journaled in bearing assemblies 100 secured to the respective side walls 31. Mounted on the drive shaft 99 on the outer side of a respective side wall 31 are a pair of sprocket gears 101. Each sprocket gear 101 is fixed on the shaft '99 for rotation therewith and in alignment with a respective sprocket gear 66 of the clampingmechanisms. A sprocket chain 102 is trained about the respective pairs of aligned sprocket gears 101 and 66 andcompletes the driving connection to the clamping mechanisms.

Centrally positioned between the side walls 31 is the article-supporting table 51. Forming the article-supporting surface of the table is a rectangular plate 106 carried by a L-shaped bracket 1197 and rocker arm 107a. A'relatively shorter leg of the L-shaped bracket 107 is pivotally secured to the lower face of the rectangular plate 106 by an elongated hinge pin 108 extending through the upper marginal edge portion of the bracket leg with the'ends of the pin journaled in respective lugs 109 attached to the plate. The opposite leg of the L-shaped bracket 107 is connected to the rocker arnr107a by a hinge structure which includes a hinge pin 110 thus permitting their relative swinging movement. Formed with the rocker arm 107a at the opposite end are a pair of axially spaced bearing sleeves 111. The bearing sleeves 111 are adapted to be journaled on an elongated shaft 112 to permit swinging movement of the L-shaped bracket 107, rocker arm 107a and plate 106 relative to the shaft 112. The shaft 112 is disposed in spaced parallel relationship to the drive shaft 99 extending transversely between the side walls 31 by which it is carried. The shaft 112 is also horizontally disposed and thus the article-supporting table 51 will swing in a substantially vertical plane to assist in the support of an article during a wrapping operation.

It is necessary that the rectangular plate 105 be coordinated in its movement relative to the rotational movement of the L-shaped bracket 107. This coordination of movement is effected by a connecting arm 113 which is pivotally connected by a pin and bracket assembly 114 secured to the rear edge of the plate 106 and operatively controlled atthe opposite end and a pair of biasing torsion springs 115. The torsion springs 115 are mounted on the hinge pin 108 and cooperatively engage the plate 106 and the bracket 107 to maintain the plate in a predetermined position to the bracket, preferably perpendicular to the shorter leg. The opposite end of the connecting arm 113 is pivotally connected to a rocker arm 116 which is journaled on the shaft 112 and is rotatable .in a vertical plane; A roller type cam follower 117 is carried by the rocker arm 116 on an arm 116a which projects a distance toward the drive shaft 99.

Control of the movement of the plate 106 and its maintenance in a desired position to advantageously support the article during the wrapping operation is effected by the drive means 54 through a connecting linkage mechanism and three cams 121, 122 and 123. The cams 121,

' 122 and 123 are mounted on the drive shaft 99 in a predetermined, fixed relationship and are rotatable therewith. Cam 121 is designed to cooperatively engage the cam follower 117 at predetermined times during a wrapping operation to effect swinging movement of the plate 105 relative to the bracket 107. (Movement of the rocker arm 10711 is effected by the cam 122 cooperatively engaging i a roller type cam follower 118 carried by an arm 119 which is'attached to one of the bearing sleeves 111. As will be subsequently explained in detail, the rocker arm 107a must be swung past a vertical position (see FIG- URE 5) in a counterclockwise direction and the neces: sary forces for effecting this movement is provided by a torsion spring 120 mounted on the shaft 112 and operatively engaged with the shaft and arm 119. The spring 120 maintains the roller 118 in engagement with the cam 122 which will thus limit the counterclockwise rotation of the rocker arm 107a. Control of the movement of the L-shaped bracket 107 is effected by a rocker arm 124 in cooperation with the cam 123. The rocker arm 124 is also journaled on the shaft 112 and is formed with an extension arm 125 which carries a roller-type cam follower 126 for engaging the cam 123. 'As can best be seen by reference to FIGURE 6, the rocker arm 124 is disposed between the axially spaced bearing sleeves 111 for optimum weight balance. A connecting link 127 pivotally connected at one end to the arm 124 by a pin 123 also connects with the bracket 107. Connection of the link 127 to the arm 124 is by a bracket and pin assembly 129.

Operation of the clamping means 50, as to both r0- tational and axial movement, in cooperation with a synchronized operation of the article-supporting table 51,

will perform a preliminary wrapping operation to the extent that the article will be enveloped in a length of the film P which is now in the form of an open-ended tube. The ends of the tube are now held and supported bythe respective opposed clamping mechanisms with the ends' being relatively flattened forming top and bottom portions; 1 The rotational movement. of the clamping mechanisms mechanisms 52 and 53 which form the bottom seal and the end flap seal, respectively.

-Referring specifically to FIGURES 4, 6 and 7, an embodiment of the foldingand sealing mechanism 52 for performing the sealing operation with respect to the bottom of the package is illustrated in enlarged scale views showing the details of construction of this mechanism. This mechanism comprises, in general, a structurally rigid frame 130 including an elongated clamping bar 131 and is carried by the article supporting table 51 for swinging I movement in a vertical plane and is supported on the table by means permitting relative swinging movement of the bar 131 and table. Supporting the clamping bar 131 is an elongated bar 132 of tubular form which is secured to i the L-shaped bracket 107 of thetable 51' and extends transversely of the apparatus. A pair of upstanding, brackets 132a are rigidly connected to the bar 132 at each end thereofwith lateral extension arms 131a of the clamping bar 131 being journaled on the upper ends of the brackets 132a whereby the clamping bar may swing in a vertical plane relative to the table bracket'107. In the present embodiment, the extension arms 131a and the clamping bar 131 are formed from tubular bars of rectangular cross section which are rigidly welded together to form a structurally rigid unit of rectangular configuration. A torsion spring 133 carried by each upstanding bracket 132a is adapted to engage a respective extension arm 131a to normally bias the arms and clamping bar 131 supported thereby in a downward, counterclockwise direction as viewed in FIGURE 4. The length of the extension arms 131a and upstanding bracket 132a are such that the clamping bar 131 will swing along an arcuate path above the normal position of the article-supporting table 51 and when in an operative, lowered position will engage the article that is being wrapped. The point of engagement of the bar with the article is preferably displaced a distance rearwardly from the mid-point.

Secured to the clamping bar 131 is a suitable heat-sealing element of the electrical resistance type which may extend substantially the length of the clamping bar. The heat-sealing element 134, as is best shown in the crosssectional view of FIGURE 13, is seen to comprise an electrical insulating body in which an electrical resistance wire 135 is embedded. The heat sealing element is secured to the clamping bar 131 on a lower surface by a suitable fastening means such as the cap screws 136. It will be noted that the heat-sealing element 134 is formed with a rounded nose for engaging the film F to prevent rupturing or tearing.

During the cyclic operation in the course of performing a wrapping operation on an article, the clamping bar 131 will be permitted to swing downwardly in response to the operation of the torsion spring 133 into engagement with the overlapped portions of the film enveloping the article. In this position, the rounded nose of the heatsealing element 134 will be in contacting engagement with the film F. The weight of the clamping bar 131 and the force of the spring 133 will maintain the overlapped portions of the film F in contacting engagement with each other and with the article being wrapped whereby a transfer of heat from the heat-sealing element 134 to the film gill effect a seal between the overlapped portions of the Controlling the movement of the clamping bar 131 is a cam 137 and linkage mechanism forming a part of the driving means 54 and mounted on the drive shaft 99 and shaft 112. A rocker arm 138 journaled on the shaft 112 by a sleeve bearing 138a carries a roller-type cam follower 139 which is adapted to engage the cam 137. The cam follower 139 is mounted on an extension of the rocker arm 138. Pivotally connected to the free end of the rocker arm 138 is connecting link 140 which is also connected to the clamping bar 131 by a bracket and pin assembly 140a. Rotation of the cam 137 as determined by the driving means 54 will thus maintain the clamping bar 131 in an elevated, inoperative position or permit the clamping bar to swing downwardly into a lowered, operative position to effect sealing of overlapped portions of the film.

At the conclusion of a bottom sealing operation as performed by the clamping bar 131 and its associated heatsealing element 134, the portion of the film F surrounding the article must be severed from the remaining web of material being unreeled from the supply reel R to permit completion of the folding operation with respect to the end folding elements. This film severing operation may be most conveniently accomplished while the clamping bar 131 is in a lowered position. Accordingly, the clamping bar 131 is provided with a suitable film severing means. In this instance, the film severing means comprises an electric current conducting wire 141 having a specific resistance such that, when energized by a predetermined electrical power source, sufficient heat will be transferred to effect a severing of the film when brought into contact therewith.

As can be seen in FIGURES 4, 5, 6, and 7, the wire 141 extends substantially the length of the clamping bar 131 and is supported by a structure permitting movement of the wire a distance outwardly from an inoperative position above the clamping bar (FIGURE 4) to an operative, severing position (FIGURE 5). Forming the supporting structure for the wire 141 are a pair of structurally rigid rods 142 which are mounted for reciprocable sliding movement in respective pairs of guide brackets 144 which are mounted on the top of the extension arms 131a. A portion of each rod 142 extends forwardly from a respective guide bracket 144 for the attachment thereto of an end of the wire 141 by resilient means 143 for maintaining the wire 141 in a taut, linear configuration. Although the wire is structurally supported by the rods 142 the wire is electrically insulated therefrom.

The opposite ends of the rods 142 extend a distance rearwardly from the brackets 144 and connect with actuating means for effecting their displacement to place the wire 141 in an operative position for severing of the film F. The end of each rod 142 is operatively connected to an electric solenoid 145 mounted on the respective arm 131a and which may be selectively energized to forwardly displace the rods 142. Return of the severing wire 141 to the inoperative position is accomplished by a pair of compression springs 148 which are mounted on the respective rods 142 between the pairs of supporting brackets 144. One end of each spring 148 operates against an abutting end of a bracket 144 and a stop collar 149 which is secured to the respective rod between the supporting brackets.

To facilitate the severing of the film F and assure continued support of the film along the longitudinal marginal edge portion, the clamping bar 131 is also provided with means engageable with the longitudinal marginal edge portion of the film to assist in supporting the film and maintaining the film in contacting engagement with the clamping bar. This means includes a pair of relatively spaced spreader fingers 151 which are carried by the clamping bar 131. Each spreader finger 151 is formed from an elongated rod of cylindrical cross section and is pivotally supported at one end for swinging movement in a plane beneath the clamping bar 131. Supporting each finger 151 for swinging movement is an elongated shaft 152 journaled in a bearing sleeve 153. The bearing sleeves 153 extend through the clamping bar 131 at an angle which will permit swinging of the fingers 151 in a plane substantially parallel to the bottom surface of the article to clamp the film F tightly to a surface of the clamping bar. The bearing sleeves 153 are rigidly secured to the clamping bar 131.

Swinging movement of each spreader finger is effected by actuating mechanism such as an electrical solenoid 154. Each solenoid 154 is secured to the clamping bar 131 by a respective supporting bracket 155. A movable armature 156 of the solenoid projects -a distance from one end of the solenoid having a number of gear teeth formed thereon. A segmental pinion gear 157 having mating gear teeth is secured to the upper end of the rotatable shaft 152 and is adapted to intermesh with the solenoid armature gear teeth. Energization of the solenoid 154 will extend the armature 156 resulting in rotation of the shaft 152 and swinging of the respective finger 151 to the clamping position shown in FIGURE 12. Return of the spreader finger 151 to an inoperative position is effected by a biasing spring (not shown) operating on the solenoid armature 156 and is effective when the solenoid is deenergized. Preferably, the fingers 151 revolve through an arc slightly greater than to avoid interference with the film F and clamping means 59.

Subsequent to completion of the bottom folding operation, the folding and sealing mechanism 53 for effecting the folding of the ends of the tubular-shaped envelope of film surrounding the article are actuated to complete the wrapping operation. The end fiap folding and sealing mechanism 53, which can be best seen by reference to FIGURES 4, 5, 6-, and 7, comprises two simi- 

9. THE METHOD OF WRAPPING AN ARTICLE IN A FILM OF RESILIENTLY PLIABLE MATERIAL CONSISTING OF RELEASABLY GRIPPING THE FILM ALONG LONGITUDINAL, MARGINAL EDGE PORTIONS AND REVOLVING THE GRIPPED PORTION OF THE FILM TO FORM A TUBULAR ENVELOPE SURROUNDING THE ARTICLE, STRETCHING THE FILM TRANSVERSELY DURING THE FORMATION OF THE TUBULAR ENVELOPE, RELEASING THE MARGINAL END PORTIONS OF THE TUBULAR ENVELOPE, FOLDING THE RELEASED MARGINAL END PORTIONS OF THE TUBULAR ENVELOPE OVER A CENTRAL PORTION OF THE TUBULAR ENVELOPE AND INTO CONTACTING ENGAGEMENT THEREWITH BEFORE 